William i



(No Model.)

W1. B-UNKBR.

' SPRING- No. 378,386. PatentedNov. 15, 1887.

UNITED STATES PATENT OFFICE.

WILLIAM I. BUNKER, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE ROCKE SPRING COMPANY, OF SAME PLACE.

.SPRING.

SPECIFICATION forming part of Letters Patent No. 373,386, dated November 15, 1887.

Application tiled August 1, 1887. Serial No. 245,775. (No model.)

To all whom it may concern..-

Be it known that I, WILLIAM I. BUNKER, a citizen of the United States, residing at Chicago, in the county of Cook and State ot'Illinois, have invented a new and useful Improvement in Springs, of which the following is al specitieation.

The object of my invention is to make a simple economical compressible spring and Io spring attachment forplatform rocking-chairs; and the invention consists in the peculiar form of a spring and combinations hereinafter described-and claimed.

In the accompanying drawings, Figure 1 is i5 a sectional elevation showing the iuside'of one of the rockers and base-rails of a platform rocking-chair equipped with my improved attachment, and Fig. 2 a side elevation of the spring detached. 2o A is the rocker; B, the base rail; C, vthe spring; c, the terminal wires; c', the extended portion thereof, and D attaching brackets.

My improved spring, which is open-coiled so as to be readily compressible, consists of two spiral springs formed from one continuous piece of wire, about as follows: rIhe wire, which must of course be of suitable length, is coiled from one end a sufficient distance to form one of the springs or body of coils, after which it 3o is bent and its straightened -portion passed through the coils formed as above, when it is again bent and coiled up or down a sufficient distance to form the other spring. In this way the two coils are formed from one con- 3 5 tinuous piece of wire, the wire terminating at the ends of the spring contiguous or near to each other.

My improved spring thus constructed can be applied to various purposes, particularly 4o where an open-coiled spiral spring is required to connect two parts together. One of the purposes to which I apply it is in platform rocking-chair attachments, and when-thus applied it is of course provided with suitable attaching-brackets.

' When used for this purpose, the attachingbrackets are adapted to be screwed onto or otherwise secured to the end coils ofthe spring, respectively, and this of course brings them close together, so that when applied they are 5o near the line of contact between the rocker and base-rail and some distance away from the outer ends of the spring. One of these attachments,- comprising two springs formed from Y one continuous piece of wire and attachingbrackets therefor, is to be used at the inside of each rocker and base-rail, and the two thus used in each chair form the main connections between its seat and base parts.

, As the essence of my invention consists in 6o the peculiar form of spring shown, I of course do not wish to be understood as limiting myselfto special features or details ot' construction; but

WhatA I claim as new, and desire to secure by Letters Patent, is-

l. As a new article of manufacture,'a compressible spiral spring comprising two bodies of coils vformed from one continuous piece of wire, and having a portion of the wire ex- 7o tended lengthwise from the outer end of one body-of the coils to the outer end of the other, substantially as described.

2. A spring attachment for platform roc-king-chairs, comprising two com pressible spiral 7 5 springs, one above the other, formed from one continuous piece of wire, and having astraightened portion of the Wire extending lengthwise from the outer end of one body of the coils to the outer end'of the other and the terminal 8o coils of the wire near to each other, and attaching-brackets for securing the springs at their respective terminal coils to the rocker and base-rail, substantially as described.

EPHRAIM BANNING, GEORGE C. Coon. 

